The invention relates to a dosing device for fabric washing machines. In particular, the invention relates to a device for dosing fabric treatment composition, and particularly rinse conditioner compositions, into a drum of a top loading washing machine in between a second and third spin cycle of the machine.
Automatic fabric washing machines generally include a number of distinct stages involving a first washing stage where the clothes are agitated with wash liquor and detergent followed by a rinse stage where the clothes are rinsed. Generally, the rinse stage comprises three separate spin cycles, a first spin to remove detergent liquor, a second spin to remove the rinse liquor added to the drum between the first and second spins, and a third spin to remove the final rinse liquor added to the drum between the second and third spins. To achieve an effective treatment of the fabrics it is advantageous to add rinse conditioner compositions to the final rinse liquor between the second and third spin cycles. heretofore this has been effected by manually adding the rinse conditioner to the drawer of the machine between the second and third spins. However, as this involves visually observing the wash until completions of the second spin cycle it is clearly an inconvenience for the user.
In an attempt to overcome the problem with manual dosing of rinse conditioners, certain machine manufacturer developed a device for automatic dosing of rinse conditioner which comprises a pair of chambers connected in parallel and integrally mounted to the drum of the machine during manufacture of the machine. In more detail, the first chamber which is exposed in an interior of the drum includes filling opening and an outlet leading to the second chamber such that during a first spin the rinse conditioner is transferred to the second chamber which lies between inner and outer drums of the machine. The second chamber includes an outlet such that during a second spin cycle the rinse conditioner is sprayed in small droplets onto the outer drum of the machine. A number of problems are associated with this device. First, as the device includes a pair of chambers mounted on opposite sides of the wall of the inner drum, the device cannot be installed in existing machines without structurally altering the drum of the machine. This is clearly inadvisable, not least for the reason that the alteration of the drum would adversely affect the delicate balancing of the drum.
Second, as the second chamber is mounted before the inner and outer drums of the machinery this result in delivering of the product onto the outer drum of the machine. In order for the product to contact the wash water it must have time to run down the side walls of the drum to the sump, however, due to the viscosity of such compositions, this can take some time resulting in an incomplete dosing of the product to the rinse water. This problem is exacerbated by the fact that due to the construction of the device the product is delivered during the second spin cycle resulting in a fine spray of small droplets onto the drum of the machine. Furthermore, the dosing of the product onto the inner drum of the machine has been found to result in a shearing effect on rotors of the drum.
It is one object of the present invention to overcome at least some of the above problems.
According to the invention there is provided a device for dosing fabric treatment composition to a drum of a top loading automatic washing machine of the type comprising a washing stage and at least two spin cycles, the device comprising at least three interconnected chambers mounted to a drum of the washing machine, namely:
a reservoir chamber having filling opening means and an outlet;
a holding chamber communicating with the reservoir chamber outlet for receiving said composition from said reservoir chamber during a first of said spin cycles; and
a dispensing chamber communicating with a holding chamber outlet for receiving said composition from said holding chamber during a second of said spin cycles, the dispensing chamber further including an outlet for dispensing said composition upon substantial completion of said second spin cycle.
Preferably, the holding chamber comprises an upper region which receives and holds treatment composition from the reservoir chamber during the first spin cycle, a lower region which delivers treatment composition to the dispensing chamber during the second spin cycle, and an intermediate region connecting the upper and lower regions such that between the first and second spin cycles the treatment composition is transferred under the force of gravity from the upper to the lower region.
Ideally, the intermediate region forms a barrier to prevent the treatment composition passing back from the lower region to the upper region during the second spin cycle.
Ideally, the upper and lower regions comprise distinct upper and lower compartments and wherein the intermediate region comprises a conduit connecting the compartments.
In a preferable embodiment of the invention the conduit is arranged on a base of the upper compartment, wherein the base is preferably shaped to funnel treatment composition into the conduit. Typically, the holding chamber has a rear wall facing a wall of the drum of the machine, and a front face, and wherein the conduit is spaced from the rear wall. Typically, a base of the upper compartment is shaped to funnel composition towards the outlet, by means of for example, the base being slanted. Ideally, a top of the lower compartment is shaped to direct the composition towards the holding chamber outlet under centrifugal force.
In one embodiment of the invention the at least three chambers are connected in series.
Preferably the device includes means for the mounting thereof to an interior of the drum of the machine. Ideally the mounting means allow retrofitting of the device.
In a particularly preferable embodiment of the invention the reservoir chamber has a rear portion adjacent the drum of the machine, an opposed front portion, and a top portion, wherein the reservoir chamber outlet means is disposed adjacent the rear and top portions of the chamber.
Preferably, the rear and top portions are shaped to funnel or otherwise bias the transfer of the composition into the reservoir chamber outlet under the centrifugal forces generated during the first spin cycle. Thus, the top and base may be slanted or curved towards the outlet.
In one embodiment of the invention the holding chamber outlet means is disposed adjacent an upper rear portion of the lower region of the holding chamber.
Preferably, the dispensing outlet is disposed towards a lower portion of the dispensing chamber. Ideally the filling chamber inlet is disposed adjacent a top of the filling chamber, and preferably spaced from the rear of the chamber away from the drum of the machine. Typically, the filling chamber includes a closure for the filling chamber inlet.
The invention also relates to a laundry washing machine comprising a device according to the invention. The combination of a device according to the invention and a fabric treatment composition, such as for example a liquid rinse conditioner, is also envisaged.
The invention also relates to a use of a device according to the invention for delivering liquid rinse conditioner to an interior of a drum of a washing machine during a rinse cycle.
The invention also relates to a process for delivering fabric treatment composition to an interior of a drum of a washing machine during a rinse cycle of the machine by employing a device according to the invention, the process comprising the steps of:
adding fabric treatment composition to the reservoir chamber prior to a start of wash cycle;
carrying out a wash stage;
carrying out the first spin cycle whereupon the fabric treatment composition is transferred under centrifugal forces from the reservoir chamber to the holding chamber;
carrying out the second spin cycle whereupon the treatment composition is transferred under centrifugal forces from the holding chamber to the dispensing chamber;
delivering the treatment composition from the dispensing chamber to the interior of the drum under force of gravity prior to and/or during addition of final rinse solution;
carrying out a final rinse cycle by agitating the fabrics, rinse solution and treatment composition for an effective period of time; and
carrying out a final spin.